Method for purifying gallium-doped pot bottom material and recovering gallium compound

Abstract

The invention discloses a method for purifying a gallium-doped pot bottom material and recovering a gallium compound, and the method comprises the following steps: 1, grinding the gallium-doped pot bottom material by using a grinding machine, removing quartz in the gallium-doped pot bottom material, cleaning the gallium-doped pot bottom material by using an acid solution, and removing residual quartz and metal impurities on the surface of the gallium-doped pot bottom material to obtain a gallium-doped silicon material; step 2, crushing the gallium-doped silicon material by using a crusher to obtain gallium-doped silicon particles; and step 3, using an acid-corrosion-resistant flower basket to contain gallium-doped silicon particles, putting the flower basket into a closed chamber, and introducing a reaction gas into the closed chamber. According to the method for purifying the gallium-doped pot bottom material and recovering the gallium compound disclosed by the invention, the gallium content in the pot bottom material can be removed in the form of the gallium compound, the gallium element is recovered and utilized, the purity of the purified silicon material is remarkably improved, the reutilization of resources is realized, the problems of resource waste and environmental pollution are effectively solved, and the method is suitable for industrial production. And the economic value of purifying the gallium-doped pot bottom material is improved.

Description

Technical Field

[0001] The invention relates to the technical field of gallium-doped pot bottom material processing, and in particular to a method for purifying gallium-doped pot bottom material and recovering gallium compounds. Background Art

[0002] In the process of semiconductor material processing, especially in the production of single crystal silicon, in order to improve the electrical properties of the material, it is often necessary to add a small amount of gallium into silicon. However, due to the segregation effect of gallium in silicon, most of the gallium will be enriched in the end of crystal growth, that is, the pot bottom material. This part of the material is usually regarded as waste material, which not only wastes gallium resources, but also increases the risk of environmental pollution. Therefore, those skilled in the art provide a method for purifying gallium-doped pot bottom material and recovering gallium compounds to solve the problems raised in the above background technology. Summary of the invention

[0003] The object of the present invention is to provide a method for purifying gallium-doped pan bottom material and recovering gallium compounds, so as to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for purifying gallium-doped pot bottom material and recovering gallium compounds, the method comprising the following steps:

[0006] Step 1: grinding the gallium-doped pot bottom material with a grinder to remove the quartz in the gallium-doped pot bottom material, and washing the gallium-doped pot bottom material with an acid solution to remove the quartz and metal impurities remaining on the surface of the gallium-doped pot bottom material to obtain gallium-doped silicon material;

[0007] Step 2: crushing the gallium-doped silicon material with a crusher to obtain gallium-doped silicon particles;

[0008] Step 3: Use an acid-resistant flower basket to hold the gallium-doped silicon particles, and place the flower basket in a closed chamber, introduce a reaction gas into the closed chamber, and heat the gallium-doped silicon particles to allow the gallium-doped silicon particles to react chemically with the reaction gas to decompose the gallium element on the gallium-doped silicon particles, thereby obtaining a gallium-doped mixed gas and silicon particles;

[0009] Step 4: extracting the gallium-doped mixed gas in the closed chamber into a condensation chamber, condensing the gallium-doped mixed gas to obtain gallium compounds, and completing the recovery of gallium compounds;

[0010] Step 5: Pure water is introduced into the sealed chamber to soak the silicon particles, and HCl gas is introduced to allow the HCl gas to contact with the pure water to form hydrochloric acid, and the gallium element and metal impurities remaining on the surface of the silicon particles are pickled to obtain pure silicon particles;

[0011] Step 6: Rinse the pure silicon particles with pure water to remove residual acid on the surface of the pure silicon particles;

[0012] Step 7: Drying the residual moisture on the surface of the pure silicon particles;

[0013] Step 8: Under dust-free conditions, package the pure silicon particles into a sealed bag to complete the purification of the silicon material.

[0014] Preferably, the acid solution in step 1 is a mixed solution of hydrofluoric acid and nitric acid, and the pickling time is 5-10 minutes.

[0015] Preferably, the particle size of the gallium-doped silicon particles obtained in step 2 is 1-5 mm.

[0016] Preferably, the gas inside the sealed chamber in step 3 is high-purity nitrogen, and the reaction gas is introduced after the internal air of the sealed chamber is fully replaced by the high-purity nitrogen.

[0017] Preferably, the reaction gas proposed in step 3 is a mixed gas of HCl and CH3I, wherein:

[0018] The chemical equation for the reaction of hydrogen chloride gas with gallium on the silicon surface is:

[0019] 6HCl+2Ga=2GaCl3↑+3H2↑

[0020] The chemical equation for the reaction of methyl iodide with gallium on the silicon surface is:

[0021] 3CH3I+2Ga=Ga(CH3)3↑+GaI3↑

[0022] H is hydrogen element, Ga is gallium element, HCl is hydrogen chloride, GaCl3 is gallium trichloride, CH3I is methyl iodide, and Ga(CH3)3 is trimethylgallium.

[0023] Preferably, the flow rate of the mixed gas of HCl and CH3I introduced into the closed chamber is 10-50 slm / min, the flow ratio of HCl to CH3I is 1:0.1-1, and the reaction time is 30-60 min.

[0024] Preferably, the heating temperature in the sealed chamber is 200-600° C., and the pressure in the sealed chamber is in the range of 0.15-0.3 MPa.

[0025] Preferably, the temperature of the condensation chamber in step 4 is 0-200°, and the obtained gallium compound is gallium trichloride crystals or trimethylgallium crystals.

[0026] Preferably, the silicon particles in step 5 are immersed in hydrochloric acid for 5-10 minutes.

[0027] Preferably, the drying temperature of the pure silicon particles proposed in step seven is 70-90°.

[0028] Compared with the prior art, the advantages of the present invention are as follows: the method for purifying gallium-doped pot bottom material and recovering gallium compounds proposed in the present invention first removes quartz and metal impurities on the gallium-doped pot bottom material by grinding and pickling to obtain gallium-doped silicon material, then crushes the gallium-doped silicon material into fine particles to obtain gallium-doped silicon particles, then puts the gallium-doped silicon particles into a closed chamber, introduces reaction gas into the closed chamber, and heats the gallium-doped silicon particles to allow the gallium-doped silicon particles to react chemically with the reaction gas to decompose the gallium element on the gallium-doped silicon particles to obtain gallium-doped mixed gas and silicon particles, then extracts the gallium-doped mixed gas in the closed chamber into a condensation chamber, condenses the gallium-doped mixed gas to obtain gallium compounds, and completes the recovery of gallium compounds, and at the same time, introduces pure water into the closed chamber. The silicon particles are soaked and HCl gas is introduced, and the HCl gas is allowed to contact with pure water to form hydrochloric acid, and the gallium element and metal impurities remaining on the surface of the silicon particles are pickled to obtain pure silicon particles. The pure silicon particles are then rinsed with pure water to remove the residual acid on the surface of the pure silicon particles, and the residual moisture on the surface of the pure silicon particles is dried. Under dust-free conditions, the pure silicon particles are packaged into a sealed bag to complete the purification of the gallium-doped pot bottom material. The quartz and metal impurities in the pot bottom material can be removed, and the gallium content in the pot bottom material can be removed in the form of gallium compounds. The gallium element is recovered and utilized, so that the purity of the purified silicon material is significantly improved, the reuse of resources is realized, the problems of resource waste and environmental pollution are effectively solved, and the economic value of the purified gallium-doped pot bottom material is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flowchart of a method for purifying gallium-doped pot bottom material and recovering gallium compounds according to an embodiment of the present invention;

[0030] Figure 2 The present invention is a process flow chart of purifying gallium-doped pot bottom material and recovering gallium compounds according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof are intended to cover non-exclusive inclusions.

[0032] Combination Figure 1 and Figure 2 As shown, a method for purifying gallium-doped pot bottom material and recovering gallium compounds comprises the following steps: step 1, grinding the gallium-doped pot bottom material with a grinder to remove quartz in the gallium-doped pot bottom material, and cleaning the gallium-doped pot bottom material with acid to remove quartz and metal impurities remaining on the surface of the gallium-doped pot bottom material to obtain gallium-doped silicon material; step 2, crushing the gallium-doped silicon material with a crusher to obtain gallium-doped silicon particles; step 3, using an acid-resistant flower basket to hold the gallium-doped silicon particles, and placing the flower basket in a closed chamber, introducing a reaction gas into the closed chamber, and heating the gallium-doped silicon particles to allow the gallium-doped silicon particles to react chemically with the reaction gas to decompose the gallium element on the gallium-doped silicon particles to obtain Gallium-doped mixed gas and silicon particles; step 4, extracting the gallium-doped mixed gas in the closed chamber into a condensation chamber, condensing the gallium-doped mixed gas to obtain gallium compounds, and completing the recovery of gallium compounds; step 5, introducing pure water into the closed chamber to soak the silicon particles, and introducing HCl gas, allowing the HCl gas to contact with the pure water to form hydrochloric acid, and pickling the gallium elements and metal impurities remaining on the surface of the silicon particles to obtain pure silicon particles; step 6, using pure water to rinse the pure silicon particles to remove the residual acid on the surface of the pure silicon particles; step 7, drying the residual moisture on the surface of the pure silicon particles; step 8, under dust-free conditions, encapsulating the pure silicon particles into a sealed bag to complete the purification of the silicon material;

[0033] The reaction gas proposed in step 3 is a mixed gas of HCl and CH3I, wherein the chemical equation for the reaction of hydrogen chloride gas with gallium on the silicon surface is:

[0034] 6HCl+2Ga=2GaCl3↑+3H2↑

[0035] The chemical equation for the reaction of methyl iodide with gallium on the silicon surface is:

[0036] 3CH3I+2Ga=Ga(CH3)3↑+GaI3↑

[0037] H is hydrogen element, Ga is gallium element, HCl is hydrogen chloride, GaCl3 is gallium trichloride, CH3I is methyl iodide, and Ga(CH3)3 is trimethylgallium.

[0038] Example 1

[0039] The method for recovering gallium compounds from gallium-doped pot bottom materials is as follows:

[0040] The gallium-doped pot bottom material was polished with a grinder to remove the quartz in the gallium-doped pot bottom material, and the gallium-doped pot bottom material was soaked in a mixed solution of hydrofluoric acid and nitric acid for 7 minutes to remove the quartz and metal impurities remaining on the surface of the gallium-doped pot bottom material to obtain gallium-doped silicon material, and then the gallium-doped silicon material was crushed with a crusher to crush the gallium-doped silicon material into gallium-doped silicon particles with a particle size of 3 mm, and the gallium-doped silicon particles were placed in a flower basket with acid corrosion resistance, and then the flower basket was placed in a closed chamber in the reactor, and high-purity nitrogen was introduced into the closed chamber to replace the internal air of the closed chamber, and then a flow rate of 30 slm / min was introduced into the closed chamber. , a mixed gas of HCl and CH3I with a flow ratio of 1:0.5 is used to make the pressure in the closed chamber at 0.2Mpa, and the gallium-doped silicon particles are heated to 400°, so that the gallium-doped silicon particles and the mixed gas of HCl and CH3I react chemically to decompose the gallium element on the gallium-doped silicon particles to obtain gallium-doped mixed gas and silicon particles. At the same time, the gallium-doped mixed gas in the closed chamber is extracted into the condensation chamber, and the temperature in the condensation chamber is controlled to be lower than 200° to obtain gallium trichloride crystals, and then the temperature in the condensation chamber is controlled to be lower than 55° to obtain trimethylgallium crystals, thereby completing the recovery of gallium elements in the bottom material.

[0041] Gallium compounds are used to remove the gallium content in the pot bottom material, thereby realizing the recovery and utilization of the gallium element and improving resource utilization.

[0042] Example 2

[0043] The method for purifying gallium-doped pot bottom material is as follows:

[0044] The gallium-doped pot bottom material was polished by a grinder to remove the quartz in the gallium-doped pot bottom material, and the gallium-doped pot bottom material was soaked in a mixed solution of hydrofluoric acid and nitric acid for 7 minutes to remove the quartz and metal impurities remaining on the surface of the gallium-doped pot bottom material to obtain gallium-doped silicon material, and then the gallium-doped silicon material was crushed by a crusher to crush the gallium-doped silicon material into gallium-doped silicon particles with a particle size of 3 mm, and the gallium-doped silicon particles were placed in a flower basket with acid corrosion resistance, and then the flower basket was placed in a closed chamber in the reactor, and high-purity nitrogen was introduced into the closed chamber to replace the internal air of the closed chamber, and then a mixed gas of HCl and CH3I with a flow rate of 30 slm / min and a flow rate ratio of 1:0.5 was introduced into the closed chamber, the pressure in the closed chamber was 0.2Mpa, and the gallium-doped silicon particles were heated to 400° to make the gallium-doped silicon particles The particles react chemically with the mixed gas of HCl and CH3I to decompose the gallium element on the gallium-doped silicon particles to obtain gallium-doped mixed gas and silicon particles. The gallium-doped mixed gas in the closed chamber is then extracted, pure water is introduced into the closed chamber to soak the silicon particles, and HCl gas is introduced to allow part of the HCl gas to contact with pure water to form hydrochloric acid, and the silicon particles are immersed in the hydrochloric acid for 8 minutes. The gallium element and metal impurities remaining on the surface of the silicon particles are pickled with hydrochloric acid to obtain pure silicon particles. The hydrochloric acid and HCl gas in the closed chamber are then discharged, and the pure silicon particles are rinsed with pure water to remove the residual acid on the surface of the pure silicon particles. The pure silicon particles are then placed in a drying box with an internal temperature of 80° to dry the residual moisture on the surface of the pure silicon particles. Under dust-free conditions, the pure silicon particles are packaged into sealed bags to complete the purification and recovery of the pot bottom material. The gallium and metal impurities in the pot bottom material are removed by grinding, pickling and chemical reaction, which significantly improves the purity of the purified silicon material, effectively solves the problems of resource waste and environmental pollution, and improves the economic value of the purified gallium-doped pot bottom material.

[0045] The working principle of the present invention is as follows: the method for purifying gallium-doped pot bottom material and recovering gallium compounds proposed by the present invention first removes quartz and metal impurities on the gallium-doped pot bottom material by grinding and pickling to obtain gallium-doped silicon material, then crushes the gallium-doped silicon material into fine particles to obtain gallium-doped silicon particles, then puts the gallium-doped silicon particles into a closed chamber, introduces reaction gas into the closed chamber, and heats the gallium-doped silicon particles to allow the gallium-doped silicon particles to react chemically with the reaction gas to decompose the gallium element on the gallium-doped silicon particles to obtain gallium-doped mixed gas and silicon particles, then extracts the gallium-doped mixed gas in the closed chamber into a condensation chamber, condenses the gallium-doped mixed gas to obtain gallium compounds, and completes the recovery of gallium compounds, and at the same time, introduces pure water into the closed chamber to soak the silicon particles. The particles are prepared by introducing HCl gas, and HCl gas is allowed to contact with pure water to form hydrochloric acid, and the gallium element and metal impurities remaining on the surface of the silicon particles are pickled to obtain pure silicon particles, and then the pure silicon particles are rinsed with pure water to remove the residual acid on the surface of the pure silicon particles, and the residual water on the surface of the pure silicon particles is dried, and the pure silicon particles are packaged into a sealed bag under dust-free conditions to complete the purification of the gallium-doped pot bottom material, which can remove quartz and metal impurities in the pot bottom material, and remove the gallium content in the pot bottom material in the form of gallium compounds, and recycle and utilize the gallium element, so that the purity of the purified silicon material is significantly improved, the reuse of resources is realized, the problems of resource waste and environmental pollution are effectively solved, and the economic value of the purified gallium-doped pot bottom material is improved.

[0046] What has been described above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for purifying gallium-doped pot bottom material and recovering gallium compounds, characterized in that: The method comprises the following steps: Step 1: grinding the gallium-doped pot bottom material with a grinder to remove the quartz in the gallium-doped pot bottom material, and washing the gallium-doped pot bottom material with an acid solution to remove the quartz and metal impurities remaining on the surface of the gallium-doped pot bottom material to obtain gallium-doped silicon material; Step 2: crushing the gallium-doped silicon material with a crusher to obtain gallium-doped silicon particles; Step 3: Use an acid-resistant flower basket to hold the gallium-doped silicon particles, and place the flower basket in a closed chamber, introduce a reaction gas into the closed chamber, and heat the gallium-doped silicon particles to allow the gallium-doped silicon particles to react chemically with the reaction gas to decompose the gallium element on the gallium-doped silicon particles, thereby obtaining a gallium-doped mixed gas and silicon particles; Step 4: extracting the gallium-doped mixed gas in the closed chamber into a condensation chamber, condensing the gallium-doped mixed gas to obtain gallium compounds, and completing the recovery of gallium compounds; Step 5: Pure water is introduced into the sealed chamber to soak the silicon particles, and HCl gas is introduced to allow the HCl gas to contact with the pure water to form hydrochloric acid, and the gallium element and metal impurities remaining on the surface of the silicon particles are pickled to obtain pure silicon particles; Step 6: Rinse the pure silicon particles with pure water to remove residual acid on the surface of the pure silicon particles; Step 7: Drying the residual moisture on the surface of the pure silicon particles; Step 8: Under dust-free conditions, package the pure silicon particles into a sealed bag to complete the purification of the silicon material.

2. The method for purifying and recovering gallium compounds from gallium-doped pan bottom materials according to claim 1, characterized in that: The acid solution in step 1 is a mixed solution of hydrofluoric acid and nitric acid, and the pickling time is 5-10 minutes.

3. The method for purifying and recovering gallium compounds from gallium-doped pan bottom materials according to claim 1, characterized in that: The particle size of the gallium-doped silicon particles obtained in step 2 is 1-5 mm.

4. The method for purifying gallium-doped pan bottom material and recovering gallium compounds according to claim 1, characterized in that: The gas inside the sealed chamber in step 3 is high-purity nitrogen, and the reaction gas is introduced after the high-purity nitrogen is used to fully replace the internal air of the sealed chamber.

5. The method for purifying gallium-doped pan bottom material and recovering gallium compounds according to claim 1, characterized in that: The reaction gas proposed in step 3 is a mixed gas of HCl and CH3I, wherein: The chemical equation for the reaction of hydrogen chloride gas with gallium on the silicon surface is: 6HCl+2Ga=2GaCl3↑+3H2↑ The chemical equation for the reaction of methyl iodide with gallium on the silicon surface is: 3CH3I+2Ga=Ga(CH3)3↑+GaI3↑ H is hydrogen element, Ga is gallium element, HCl is hydrogen chloride, GaCl3 is gallium trichloride, CH3I is methyl iodide, and Ga(CH3)3 is trimethylgallium.

6. The method for purifying gallium-doped pan bottom material and recovering gallium compounds according to claim 5, characterized in that: The flow rate of the mixed gas of HCl and CH3I introduced into the closed chamber is 10-50 slm / min, the flow ratio of HCl to CH3I is 1:0.1-1, and the reaction time is 30-60 min.

7. The method for purifying and recovering gallium compounds from gallium-doped pan bottom materials according to claim 1, characterized in that: The heating temperature in the sealed chamber is 200-600° C., and the pressure range in the sealed chamber is 0.15-0.3 MPa.

8. The method for purifying gallium-doped pan bottom material and recovering gallium compounds according to claim 1, characterized in that: The temperature of the condensation chamber in step 4 is 0-200°, and the obtained gallium compounds are gallium trichloride crystals and trimethylgallium crystals.

9. The method for purifying gallium-doped pan bottom material and recovering gallium compounds according to claim 1, characterized in that: The silicon particles in step 5 are immersed in hydrochloric acid for 5-10 minutes.

10. The method for purifying gallium-doped pan bottom material and recovering gallium compounds according to claim 1, characterized in that: The drying temperature of the pure silicon particles proposed in step 7 is 70-90°.

Images